This lid is a modern, better than original replacement lid for the A-R12 lid. This lid is made from High Density Acrylic. Factory original lids are made from HDPE plastic, while good for strength, it has a very poor resistance to abrasion. As you may well know, these lids may wear thin after only a few tumblings, causing leaks. The acrylic replacement lid here is far Superior to factory original, in both strength and abrasion resistance. The physical property comparison of the two materials are as follows: ACRYLIC HDPE Density 1.18g/cc .96g/cc Hardness, (Rockwell R) 110 50 Tensile Strength 8000psi 3200psi These lids are over Twice as strong as original lids. This lid will replaces both old and new style lids, and will fit perfectly. This is a non factory original A-R12 barrel lid, for the popular Thumler's Tumbler brand Tumbler/Polisher but works just as well. This sale is for the lid only, no retainer ring, no tumbler included, just one replacement barrel lid. This lid is approximately 6 inches in diameter, it will only fit the AR 12 series. **This Lid Is Better Than** **Original Factory** Sale Is For One(1) Brand New Lid Only, NO Tumbler, No Other Parts, Just What is In The Picture.